Latch mechanism



April 25, 1961 A. P. wEHNER LATCH MECHANISM Filed sept. 11, 1958movement between the positions.

.i accompanying drawings inwhich: Y l i top View of oneemblodiment ofthe present invention; l .j l M .1 1 j Fig.i 2 rsan enlarged cross-sectien of a latch embodying A zthe present invention, l takenalong da line `substantially l corresponding with line` 2j-2.of' Fig.`Lgf; 'A

The present` invention relates to latches for doors, drawers and thelike and more particularly to a new mproved latch mechanism of simple,rugged construction and ease of operation and has for an object theprovision of a child proof latch readily operated by adults.

Countless accidents occur when children obtain access to drugs, poisonsand the like stored in medicine cabinets and closets.

The attempts in the past to keep drugs and dangerous instrumentalities,such as guns, from children have ernployed key operatedV locks and socalled secret or hidden fasteners. While such arrangements are for themost part successful they are subject to failure unless the key 2 Fig. 4is a cross-section of another modification of the present invention; and

Fig. 5 is aperspective view ofa casing employed in the modification ofFig."4.

Referring now to Fig. V1 there is illustrated a latchV mechanismembodying the present invention and shown in a drawer locking relation`with a latching means llldisposedr adjacent drawer 12. The latch 10 isshown secured toja fixed drawer ordoor frame 13 of a cabinet by means ofa base portion 14. In accordance with the present invention the latchmechanism may be mounted readily and with the use of the simplest toolsto existing furniture withoutthe need for boring holes or otherwiserequiring `the services of `a cabinet maker. More particularly the latch10 is shown secured to the frame `13 by way of wood screws 15;

The latchingmeans 11 isgrotatably moveable out of locking engagementwith the drawer 12 by the application of pressure upon the top of acasing or tube 16 to release, as described in detail here-in-after, `thelatching means 11 for movement to a position over the base 14 and awayfrom the drawer 12. The area of upper surface of the tube or casing 16is purposely made small so as to limit the operation of pressureapplication to` a single tingen For example thediameter of the upper i YLsurfacepreferably is no larger than one inch. Whilean is kept out ofthe hands of the children and `thefoperation of the hidden or secretfastener takes placeunseen by the children.

The problem of preventing small children from openuse of greatersustained force than the child is capable of applying. Y e

In accordance with the` present invention there is employed a releasemechanism operable solely by pressure to be exerted by one finger.

More particularly and in accordance with the present` invention there isprovided a latch comprising `a Vfirst cylindrical casing having aslotportion of which extends at least in part peripherally of the casing andhaving a further portion which extends toward the bottom of the casing.A second cylindrical casing isjmounted coaxially with the first casingand thecasings are rotatably moveable relative to each other. A drawerengaging means is secured to one of the casingsjand extends radiallyouti Wardly from and moveable wtih the casing from a drawer engagingposition to` a drawer disengaging position.

means including the slot is provided for locking the engaging means inthe positions. The casings are also moveable axially relative to oneanother against force exerted by a spring to release the engaging meansfor Forother objects of the present inventionand attendanty advantagethereof reference may be had "to the fol- Y lowing detailed descriptiontaken in conjunction with the v VFig. l isa adult is capablevof applyingthe sustained pressure necessary to release the' latch a small'child isincapable of applying such force with the one finger by which theapplicationof pressuremust be exerted. i `Construction details .of the`latch are illustrated in Fig. 2 wherein the lirst casing or tube 16 isshown mounted coaxiallyor concentrically with a second casing 17.

`cooperating ring 19` secured to the base 14, for example by Way of`rivets 20, and having inwardly disposed flange portion 21 for engagementwiththe flange 18 of the `casing 17.1`

,The `latching means 11 is shown forming an integral part "of.thefcasing 17.'` Itis to be understood however that the `latching meansor drawer engaging arm 11"may be separately formed and secured to` thecasing' as by way ofmachine screws (not shown) or `by'welding the Yengaging arm or latching means 11 to the outside surface r of the`casing 1-7. f It is preferred that the latching means 1 22 formed-ofrubber or other resilientmaterialand secured iniany desired manner, forexample, as by way of machine screw ,23,` to the underside of the armorlatchform an integral part ofthe casing for maximum strength -inasmuchas it is` `contemplated that the drawer 12 will be vigorouslyldrawnagainst thearm or latching `means 11 byA children attempting to open'it.In this regard, in order to prevent the marring of the finish of thedrawer 112,` the latching means` may be provided with a cushion Thelatching means or ann 11V is maintained in `either including a rod 2.4,a `sleeve V25, aslot 26 formed in the casing 164and a projection or pin27 extending inwardly Fig. 2 with a portion cut away showing featuresofzconfrom the1 inner surface ofthe casing 17. Thegrod 24, shown-as,integral with thefbase` 14, is provided with at least oneand preferablytwo projections 23 extending into andf otherwise received by. slots 29formed in the sleeve L `25 depending from thefunderr surface of the"casing 16.

. i j. i 70` of amodication ofkthe With the "constructionthus"?fardescribed and with the A ing the ring to the base.

may be employed or the ring may be welded to the base.

V14 and that its motion is limited to an axial movement relative to thecasing 17 against the force of a spring 30. With the projection 27engaging the walls of the slot 126 theV latching means 11 will belockedin a drawer engaging position until such Vtime as the casing'16 is moved'axially against-the force of the spring 30 to release and otherwiseallow rotation of the latching means 11 to a drawer disengaging positionand in a manner now to be described. Y

Referring now to Fig. 3 the slot 26 is shown comprised of at least threeportions; a vertical portion 31 extending from the bottom of the casing16, a horizontal portion 32 and a second vertical portion 33 at theopposite end of kthe horizontal portion 32. The latching means isreleased when the casing 16, Fig. 2, is lowered to a position whereinthe horizontal portion 32 of the slot 26 is opposite lprojection 27. AtthatV time the latching means 11 may be rotated freely with theprojection 277 riding in thehorizontal slot 32 to a position adjacentthe slot 33.

-Now upon release of pressure from the top of the casing 16 the spring30 Vwill move the casing upwardly and the projection 27 will ride in theslot 33 to the lower portion thereof to lock the latching means 11 indrawer disengaging position.

lthe latching means to proper locking relation with the :drawer at whichtime the projection 27 will enter slot-31.

Under inuence o-f spring 3i) thev projection 27 is guided relative tocasing 17 and along slot 31 to lock the latch- V ing means in a drawerengaging position.

With the latching means 11 in drawer engaging position the upwardmovement of casing 16, as caused byspring 39, is limited by,means'rincluding a shoulder 34 Vat least in part peripherally formedabout the bottom portion of the casing 16 and a sleeve 35 threadablymounted on the casing 17 and having an inwardly disposed flange ,36engaging the shoulder 24.

While the ring 19 mounting the casing 17 to the base 14 has beendescribed as riveted to the base Vit will be understood that other meanscan be employed for secur- For example machine screws ln a preferredembodiment-the ring 19 isforrned in two pieces in order to facilitateassembly ofthe latching"Y mechanism.

A wide choice of materials known to those skilledl in the art areavailable for construction of the latch mechanism of the presentinvention. The spring should be of durable spring-steel having, whenformed, a compliance which will defy compression of the spring by smallchildren seeking'to release the latch. The latch of the presentinvention, as above described, will provide a latching means of smallsize and of simple operation yetV will be n effective to keep materialsharmful to children readily accessible for considered use by adults andout of the Yhands of children,V

Now that one embodiment has been fully described otherembOdimentS', allwithin the 'scope of the'present 12.,."111 Fig. 3a there is illustrateda y*modification in which the depression'of the casing 16 automaticallywill rotate'the' latching means into and, out of engagement -with thevdrawer 12 thus providing one-finger operation fof the latch', Moreparticularly Ysuch operation is provided by providing a slot' 0in a formof helixhavingan open f end at the bottom of a casing 16ifand havinga'vertically rdepending lslotted -portion M4-'The' portion 41 functionsin a manner similar to the slotted portion 33 of Fig. 3 in order toprovide a locking of the latching means in a drawer disengagingposition. The locking of the latching means in a drawer engagingposition is provided by a short portion 42 of the slot 4t) beingsubstantially vertical such that the casing 16a will have to be moved ashort vertical distance before rotationof the latching means commences.In operation the depression of the casing 16a will cause the walls ofslot 40 to apply a force to the projection 27, Fig. 2, which force willbe translated into a rotation of the latching means as the projection 27continues to ride along the walls of slot 40. .j

Yet another modification of the present invention /is illustrated inFig. V4 wherein a latching means 11b is shown forming an integral partof the first or outer casing 16b `and in which the slots, whichcooperate with arprojection to provide the locking of the latch means indrawer engaging and drawer disengaging position, are formed` provide arough surface for ease of transmitting rotational motion from the fingerto the casing.

One arrangement of slots suitable for use in the modification in Fig. 4is illustrated in perspective .in Fig. 5. The slots include a firstvertical portion Sib, a horizontal portion 32h and, at an opposite endof the horizontal portion, a substantially vertical depending portion3.3i). These slotted portions cooperate in the same Vmanner as theportions 31-33 of Fig. 3 to provide in part a'means forlocking,releasing and for moving the latching means between two selectedpositions. shorter slot portion 31b locks the latching means in a drawer'disengaging position while the longer slotted portion 3319 locks thelatching means in a drawer engaging position. While both the slot 31band 33h may be of the same size it is preferred to make the slot 33hdeeper in order to require a sustained Vforce of relatively longduration for releasing the latching means from a drawer engag-Y ingposition. Thus while a child mayhave sufficient strength to beginrelease of the` latch he will be unable to sustain the pressure requiredto complete the release vided for the ready assembly ofthe componentparts of the latching mechanism. In such assembly the upper or outercasing leb is mountedoverthe casing 17h w1th theextension 27h within theslot 47. Pressure is applied i to the top of the casing 16h and againstthe force of the spring Stib to move the extension or extending portion27b along the slots 47, i6 and 45 to a position where the extendingportion is received by the slot 3J). Y

While the various embodiments ofthe present Yinvention have `beenillustrated as mounted on a frame adjacent a drawer as by way of basev14 it will be understood that whenthe construction ofthe door ordrawerdictates adapters -may be employed for proper mounting of the latchmechanism. f

Y Nowl that the invention has been described and several modificationsset forth it will be apparentthat `stillfurther modificationswillsuggest themselvesto those skilled in the art and it is intended tocover such modifications by'the appended claims.:l

What isclairned is:

f A latchfcomprising a first. cylindrical casingwhaving a slot includinga portion extending at least in part pe- More particularly theripherally thereof and having a further slotted portion extending towardthe bottom of said casing, a second cylindrical casing mounted coaxiallywith said first casing and having a first projection extending into saidslot, a base for mounting to a xed surface adjacent the edge of adrawer, a vertically extending rod secured to said base and having asecond projection intermediate its ends extending outwardly, a sleevedepending from one of said casings for receiving said rod, said sleevehaving at least one vertical slot into which said second projectionextends for locking said one of said casings against rotation relativeto said base, the other of said casings being rotatably mounted to saidbase, drawer engaging means secured to said other of said casings andextending radially outward from and moveable with said other of saidcasings between a drawer engaging position and a drawer disengagingposition, means including said rstmentioned slot and said rst projectionextending into said further slotted portion for locking said drawerengaging means in said positions, said casings being axially moveablerelative to one another to position said iirst projection into saidperipheral portion of said slot for releasing said drawer engaging meansfor movement between said positions, and a spring for normally urgingsaid casings apart.

2. A latch as in claim l in which said one of said casings is providedwith a shoulder portion extending at least in part around circumferencethereof and in which said other of said casings is provided with aninwardly disposed flange for engagement with said shoulder portion tolimit the axial movement of said one of said casings in a direction awayfrom said base.

3. The latch of claim 1 in which said one of said casings is providedwith a top surface to which force may be applied to move said one ofsaid casings downwardly to release said drawer engaging means formovement be tween said positions.

4. A latch mechanism for a drawer and adapted for mounting on a surfaceadjacent to and fixed relative to the drawer comprising a base formounting to the surface, an outer cylindrical casing, an innercylindrical casing mounted in telescoping relation with said firstcasing and having an end extending `above said rst casing, one of saidcasings being mounted at one end thereof to said base, a drawer-frontengaging arm mounted on and intermediate the ends of said outer casing,said arm being moveable about said inner casing between adrawer-engaging position and a drawer-disengaging position, means onsaid inner casing for locking said arm in either of said positions, andmeans at the top of one of said casings for moving said one of saidcasings downward to release said arm for movement between saidpositions.

5. A latch assembly for a drawer and adapted for mounting on a surfaceadjacent to and fixed relative to the drawer comprising a base formounting to the surface, an outer cylindrical casing mounted at one endthereof on said base, an inner cylindrical casing mounted in telescopingrelation with said outer casing and having an end extending above saidouter casing, a drawerfront engaging arm mounted on said outer casingand normally positioned intermediate the ends of the assembly, said armbeing moveable about said inner casing between a drawer-engagingposition and a drawer-disengaging position, means on said inner casingfor locking said arm in either of said positions, and means at -the topof said inner casing for moving said inner casing downward to releasesaid arm for movement between said positions.

6. A latch comprising an inner cylindrical casing having a slotincluding a portion extending at least in part peripherally thereof andhaving a further slotted portion extending toward one end of said innercasing, an outer cylindrical casing mounted coaxially with said innercasing and having a projection extending into said slot, a base mountedto one end of one of said casings for securing the latch to a xedsurface adjacent a surface moveable with respect thereto, said casingsbeing rotatably moveable relative to each other, means for engaging themoveable surface and secured to said outer casing, said engaging meansbeing moveable with said outer casing from a moveable surface engagingposition to a moveable surface disengaging position, means includingsaid slot and said projection extending into said further slottedportion lfor locking said engaging means in said surface engagingposition, said casings being axially moveable relative to one another toposition said projection in said peripheral portion of said slot forreleasing said engaging means for movement between said positions, andmeans normally urging said casings axially apart.

7. A latch as in claim 6 in which said slot is in part a helix and withsaid projection extending into said helix rotates said outer casing tomove said engaging means between said positions as said inner casing ismoved axially of said outer casing.

8. A latch as in claim 6 in which said outside vcasing is rotatablymounted to said base.

9. A latch as in claim 8 in which a helical spring within said casingsprovides said urging means to move said inner casing away from said baseto lock said engaging means in said moveable surface engaging position.

References Cited in the tile of this patent UNITED STATES PATENTS521,341 Gardner June 12, 1894 776,178 Guedeney et al Nov. 29, 1904948,119 Wettig Feb. 1, 1910 2,051,132 Dart Aug. 1S, 1936 42,276,915 Axeet al Mar. 17, 1942 FOREIGN PATENTS 729.751 France May 2, 1932.

